Building assembly and cant strip



Nov. 22," 1938.

BUILDING ASSEMBLY AND CANT STRIP Filed June 13, 1936 INVENTOR WILL.AM GlL-LETT.

ATTORNEY w. GILLETT 2,137,335,

Patented Nov. 22, 1938 PATENT OFFICE I ;..-.2.1s7,ss9 l BUILDING ASSEMBLY Ann'o N'rsmug. j

William Gillett, permit, Mich.

Application June 1a. 1936, Serial No. 84,995

2 Claims.

This invention relates to a building assembly and, particularly, to a cant strip for use therein. There are numerous types of flashing for joints in a building, as, for instance, between a roof and 5 a parapet wall.

Also, the application of thermal insulation to roofs has decreased largely the formation of dew on the underside of the roofs. When dew does form, one of the most objectionable places for its formation is at the side of a roof, from which place the condensed dew may run down the side walls of the building, with production of streak- At the same time, it is at this particular location that the formation of dew is most diflicult to avoid. Thus, the parapet wall in winter produces considerable cooling of the adjacent portions of an insulated roof.

It is an object of the invention to overcome this excessive tendency to dew formation at the meeting place of the roof and side wall. Another object is to provide an improved flashing strip that is an effective thermal insulator. Other objects and advantages will appear from the detailed description that follows.

The present invention comprises the novel features hereinafter described in connection with a flashed building assembly or cant strip and, particularly, a cant strip that is lightweight, thermal insulating and resiliently compressible, these terms being used to distinguish my improved strip from the previously used flashing members constituted largely of asphalt or equally heavy material not possessing resilient yieldability and not being effective insulators.

The invention is illustrated in the attached drawing and will be described in connection therewith.

Fig. l is a perspective view of a building assembly flashed in accordance with my invention and showing certain parts broken away for the purpose of illustration.

Fig. 2 is a cross sectional view of a cant strip suitable for use in the assembly if Fig. l. Referring to Fig. 1, there is shownl a roof which, for the purpose of illustration, may include a ribbed metal deck II, a layer of thermal insulation l2, such as lightweight fibre board, disposed over the deck, and an outermost layer I3 of waterproofing material that may be conventional built-up roofing including asphalt-impregnated paper.

My improved flashing strip l5 flashes the joint between the wall and the roof, as illustrated. Suitably, the flashing strip is coated on all lateral surfaces as well as at its ends with a waterproofing material such as a layer of asphalt (not shown).

The layer I3 of built-up roofing or the like extends, preferably, over the outer face of the strip l5 and for anappreciabledistance up the side of the parapet wall.

The cant strip is suitably constituted of a plurality of plies of the selected composition, with layers l6, l1, and 18 of adhesive material selo curing the several plies together.

The adhesive layers are preferably waterproof. Thus, they may be constituted of a bituminous composition such as asphalt. The said layers are spaced from each other, extend longitudinally through the strip, and lie each in a plane parallel to the surface or face IQ of the strip that is outermost when the strip is in use in the flashed assembly. Such an arrangement m causes proper shedding of water and promotes overall flexibility of the strip.

The composition .of the cant strip is not only thermal insulating and resiliently yieldable, as stated, but also is constituted, preferably, of felted fibrous material such as insulating fibre 25 board of conventional type, supplemented by a waterproof exterior envelope and/or inwardly disposed waterproof layers, as described.

I have used to advantage a cant strip constituted of a plurality of plies, say 4, of wood fibre 30 insulating board each of half-inch thickness, the plies being adhered together by casein adhesive or asphalt.

A common type of thermal insulating fibre board that I have used weighs about 15 to 20 35 pounds to the cubic foot and has a specific thermal conductance of the order of 0.33 to 0.37, in the engineering system of units.

The functioning of the cant strip may be illustrated by considering the behavior of the as- 40 sembly on an interiorly heated factory building, in very cold weather. The insulation I2 is adequate to prevent such a low temperature over the major portion of the roof as to avoid formation of dew under the roof deck ll. However, at the edge portions, the cold parapet wall conducts heat away from the roof deck. There is thus produced, unless my improved cant strip is used, a low temperature that may cause dew formation under very certain humidity oondi- 50 tions within the building.

The use of my thermal insulating cant strip adds sufficient insulation, at the critical side portion of the roof, to minimize the temperature difierence between the edge portion and the main 55 portion of the roof deck and thus decrease the probability of the formation of dew and consequent streaking of the side walls of the building thereby under any ordinary condition of use of the structure.

In addition to minimizing the possibility of the formation of dew, the lightweight strip is easy to handle and install, relatively inexpensive to manufacture, readily sawed or cut to proper length on the roof, and conforms well when pressed against somewhat irregular surfaces that are to be flashed.

It will be understood that the details given are for the purpose of illustration, not restriction; and that variations within the spirit of theinvention are intended to be included in the scope of the appended claims.

I the strip that is to be outward in the flashed 1 assembly.

WILLIAM GILLETT. 

